boost/spirit/home/classic/meta/as_parser.hpp
/*=============================================================================
Copyright (c) 2002-2003 Joel de Guzman
Copyright (c) 2002-2003 Hartmut Kaiser
http://spirit.sourceforge.net/
Distributed under the Boost Software License, Version 1.0. (See accompanying
file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
=============================================================================*/
#if !defined(BOOST_SPIRIT_AS_PARSER_HPP)
#define BOOST_SPIRIT_AS_PARSER_HPP
#include <boost/spirit/home/classic/namespace.hpp>
#include <boost/spirit/home/classic/core/primitives/primitives.hpp>
namespace boost { namespace spirit {
BOOST_SPIRIT_CLASSIC_NAMESPACE_BEGIN
///////////////////////////////////////////////////////////////////////////
//
// Helper templates to derive the parser type from an auxilliary type
// and to generate an object of the required parser type given an
// auxilliary object. Supported types to convert are parsers,
// single characters and character strings.
//
///////////////////////////////////////////////////////////////////////////
namespace impl
{
template<typename T>
struct default_as_parser
{
typedef T type;
static type const& convert(type const& p)
{
return p;
}
};
struct char_as_parser
{
typedef chlit<char> type;
static type convert(char ch)
{
return type(ch);
}
};
struct wchar_as_parser
{
typedef chlit<wchar_t> type;
static type convert(wchar_t ch)
{
return type(ch);
}
};
struct string_as_parser
{
typedef strlit<char const*> type;
static type convert(char const* str)
{
return type(str);
}
};
struct wstring_as_parser
{
typedef strlit<wchar_t const*> type;
static type convert(wchar_t const* str)
{
return type(str);
}
};
}
template<typename T>
struct as_parser : impl::default_as_parser<T> {};
template<>
struct as_parser<char> : impl::char_as_parser {};
template<>
struct as_parser<wchar_t> : impl::wchar_as_parser {};
template<>
struct as_parser<char*> : impl::string_as_parser {};
template<>
struct as_parser<char const*> : impl::string_as_parser {};
template<>
struct as_parser<wchar_t*> : impl::wstring_as_parser {};
template<>
struct as_parser<wchar_t const*> : impl::wstring_as_parser {};
template<int N>
struct as_parser<char[N]> : impl::string_as_parser {};
template<int N>
struct as_parser<wchar_t[N]> : impl::wstring_as_parser {};
template<int N>
struct as_parser<char const[N]> : impl::string_as_parser {};
template<int N>
struct as_parser<wchar_t const[N]> : impl::wstring_as_parser {};
BOOST_SPIRIT_CLASSIC_NAMESPACE_END
}} // namespace BOOST_SPIRIT_CLASSIC_NS
#endif
